Committee of Experts on the Transport of Dangerous Goods and on the Globally Harmonized System of Classification and Labelling of Chemicals
Sub-Committee of Experts on the Transport of Dangerous Goods
Forty-first session
Geneva, 25 June – 4 July 2012
Item 3 (a) of the provisional agenda
Listing, classification and packing:
proposals of amendments to the list of dangerous goods of Chapter 3.2
Guiding Principles at Part 4.3 C – tank instruction assignments for UN Portable tanks
Transmitted by the expert from the United Kingdom
Introduction
1. At the fortieth session of the Sub-Committee the expert from the United Kingdompresented document ST/SG/AC.10/C.3/2011/37 regarding transitional periods for UN portable tanks intended for the transport of liquids. The paper presented two proposals. One to amend the guiding principles in relation to providing guidance on changing the assignment of one tank instruction to another and a second proposal to extend transitional periods already adopted.
2. The second proposal to extend the transitional periods already adopted was not supported by the Sub-Committee but there was support for the development of Guiding Principles. The extract from the official report ST/SG/AC.10/C.3/80 is reproduced below:
“63. Several experts supported the idea of establishing guiding principles for the amendment of portable tank transport codes assigned to specific substances, however they had some reservations about the proposed texts. For example, the reference in paragraph 9 to a catastrophic failure should be deleted, as it might give the impression that assigned codes were amended in reaction to accidents, when in actual fact amendments were introduced to anticipate and avoid accidents. Similarly, the transitional period of 15 years considered in paragraph 11 was excessively long. Some experts said that the transitional periods should be determined on a case-by-case basis, in the light of the safety requirements and actual economic repercussions.”
3. The United Kingdomexpert has considered the comments received at the last meeting and has amended the proposal for the guiding principles.
Proposal
4. The following is proposed text for the Guiding Principles at Part 4.3 C. The text presented in square brackets is for discussion by the Sub-Committee based on the differing opinions expressed at the last meeting.
Insert the following text after section B and renumber existing sections C and D accordingly:
“C. Guidance on changing the assignment of one portable tank instruction to another for particular substances
• The rationalized approach taken to portable tank instruction allocation should be followed. It should not be necessary to change an existing portable tank instruction allocation to a particular substance or group of substances to a higher specification portable tank unless:
• There is a demonstrable reason to believe that a failure might occur which is related to the construction of the tank thus requiring an upgrading of the portable tank instruction assignment;
• A demonstrable positive cost benefit case indicates an improvement for safety, environmental protection or operational reasons;
• Amendment is made to the guidance on portable tank instruction assignment in section 4.3 B of these Guiding Principles.
Any change in the portable tank instruction allocation should not be in contradiction with the rationalized approach.
Where a change of tank instruction is considered necessary having regard to the principles set out above, consideration should be given to the following points to help determine to which tank instruction should now be applicable/desirable to move to and whether this then modifies the original decision to change the tank instruction in the first place:
• Whether the change means that the existing portable tank cannot be modified for continued use because it requires a change of shell thickness, tank volume, such as a tank constructed for a high density substance or a change from openings below the level of the liquid to no openings below the liquid level (top discharge portable tanks);
• The impact on consignors and consignees in having to modify filling plant to accept top opening portable tanks in terms of the required capital expenditure and the time needed to modify the filling plant;
• The reduced possibility for owners and operators to fill the portable tanks on both the outbound and return journey when the portable tank instruction is changed from bottom opening to top discharge portable tanks including the complications which ensue for cleaning the portable tanks. (Such portable tanks may, de facto, have to become dedicated to the transport of just one substance).
• Where it is deemed necessary to re-assign a substance to a different specification portable tank instruction, consideration should be given to permitting the existing portable tank to continue in its existing use for the remainder of its useful life or the provision of a transitional period [of 10 years] [of 15 years] [to be determined on a case by case basis] is established. An appropriate Tank Provision (TP) shall be issued to specify the period of use.”
联合国危险货物运输专家和全球化学品统一分类和标签制度专家委员会
危险货物运输专家分委员会
第四十一次会议
日内瓦, 2012年6月25日-7月4日
议程第 3 (a) 项
列表，分类和包装：对修订3.2章危险货物列表的提案
指导原则4.3 C部分–UN便携式罐体的罐体说明分配
由英国专家提交
介绍
1. 在分委员会第四十次会议上，来自英国的专家提出关于运输液体的UN便携式罐体的过渡期的提案ST/SG/AC.10/C.3/2011/37。这份文件提出了两项提议，其一是修订关于改变罐体说明（由一个说明改为另一个）的指导原则，其二是延长已采用的过渡时期。
2. 虽然对于第二项延长已被采用的过渡期的提议并未获得分委员会的支持，但他们对于扩展指导原则是支持的。以下摘录了正式文件ST/SG/AC.10/C.3/80中的内容：
“ 63. 有几位专家支持建立修订特定物质的便携式罐体运输编码的分配指导原则，然而他们对于提议的内容仍持有些保留意见。例如，第9段中关于灾难性事故的内容应该被删除，不然这样很容易让人感觉对于编码分配的修订是与事故有关，但实际上的修订是预防和避免事故。同样地，在第11段中考虑的15年的过渡期也太长了。一些专家提出，应该根据安全的需求和实际的经济影响，按照个案确定过渡期的长短。”
3. 英国专家考虑了上次会议中收到的评论，修订了关于指导原则的提案。
提议
4. 以下是关于4.3C部分指导原则的提议内容。方括号中的文字是上一次会议中分委员会讨论后中的不同观点。
在B部分文本之后插入了如下内容，并对C和D部分进行了重新编号：
“C. 关于特定物质的便携式罐体说明分配改变的指导原则
• 对于便携式罐体说明的分配应该遵从合理的方法。对于将特定物质或是一组物质现有便携式罐体的规范分配改变到更高规格的便携式罐体并非是必须的，除非：
• 有显而易见的理由让人相信，由于罐体的构造可能会发生故障，因而需要提高便携式罐体说明；
• 有显而易见的确实的成本效益的案例表明有利于提高安全，环境保护或操作原因。
• 对4.3B部分关于便携式罐体说明分配的这些指导原则进行的修订。
任何对于便携式罐体说明分配的改变都不应该与合理的方法相矛盾。
根据上述所列的原则，认为有必要对罐体的说明进行改变时，考虑如下几点有助于确定哪种罐体的说明对于现在来说是合适的/令人满意的，以及这样是否改变了修改罐体说明的最初决定：
• 是否这种改变意味着现有的便携式罐体不能修改而继续使用，因为它需要改变壳壁厚度，罐体容积，例如为了适合承装高密度物质建造的罐体或者将罐体从液面以下开口改为液面以下无开口(顶部排放便携式罐体)；
• 为了接受顶部开口的便携罐，他们需要资金支出来调整灌装工厂，同时调整也需要时间，这对托运人和收货人都会带来影响。
• 由底部开口便携式罐体变为顶部排放便携式罐体，包括由此带来的便携式罐体清洗问题，使得所有者和经营者在便携式罐体出港和返港中都装货的可能性降低。（这样的便携式罐体，可能实际上变成了一种物质运输的专用罐体）
• 当一种物质被认为需要重新分配一个不同规格的便携式罐体说明时，应考虑允许在过渡期[ 10 年] [ 15 年] [具体问题具体分析]仍然可以继续使用现有的便携式罐体。应该提出适当的罐体规定(TP)来详细说明使用周期。”